Crystal detector



May 15, 19231 1,454,997

G. GRECO ET AL CRYSTAL DETECTOR Filed April 18, 1922 awn/r02 am a 77 BY ATT mm.

30 base plate latented May 15, 1923.

GAETANO canoe AND KARL e. woLrr, or ivnwenx, NEwlJERsnYL j CRYSTAL DETECTOR.

Application filed April 18, 1922. Serial No. 554,555.

T all whom it may concern: 1

Be it known that we, GAETANO Gmzoo and KARL G. l/VoLrF, citizens of Italy and of Germany, respectively, and residents of 6 Newark, county of Essex, and State of New Jersey, have invented certain new and useful Improvements in Crystal Detectors, of

which the following is a specification.

This invention relates to an improved crystal detector for wireless receiving sets,

and is adapted to be placed in position in a set and is easily accessible for adjustment,

if the small wire engaging the piece of crystal becomes dislodged from a detecting point, by the removal of the dust-proof cover, which cover fits over a block on which the crystal is mounted and through which the detecting wire passes, the cover fitting within an annular flange of a bottom plate to Which the block is secured.

The invention is illustrated in the accompanying drawing, in which Figure 1 is a sec tion of a crystal detector made according to our invention. Figure 2 is a top view of the device shown in Figure 1, and Figure 3 is a bottom view of the device shown in Figure 1.

The detector comprises a block 10 made of insulating material, which is mounted on a 11, the base plate 11 having an annular flange or bulged part 12 thereon spaced from the block 10 so that a domeshaped cover 13 can be slid down to be grasped and held against dislodgment,

3 since the block 10 is spaced from the flange 12 sufficiently to permit a tight fit between the bottom of the cover 13 and these elements, the cover 13 being preferably made of glass.

The device is held down byrmeans of a bolt 14, the head 15 of which en ages a sheet 16 of insulation, and a nut 1 is arranged on the screw-threaded end of the bolt 14 to clamp a washer of insulation 18 against the bottom of the base plate 11.

The fastening nut 19 and the binding nut 20 are arranged on the bolt 14, the nut 19 to hold the device on a suitable table or support 21, and the nut 20 to hold the end of a wire 22. The other wire 23 of the circuit is secured to the base plate 11 by solder or by.

a screw 24, the latter being preferred, and

is soldered or otherwise secured, as at 25, to the bottom of the block 10, and projecting through it, and having an open looped end 26, is the contact wire 27.

The washer 18 of insulation is usually expansive enough to protect the base plate 11 from contact with the bolt 14, and is preferably cut away, as at 28, to give room for convenience of attachment of the wire 23 and for soldering the end 25 of the. wire 27. Secured to the head. 15 of the bolt 14 is a block of metal 29 into which the piece 30 of crystal is embedded. 1

Under normal use there will seldom be any necessity for readjustment of the end 26 of the wire 27, so that the wire is substantially in fixed position as supplied by the dealer to the purchaser, the end of the wire having been previously set on a good detecting point.

e claim:

1. A crystal detector comprising a block of insulating material, a bottom plate on which the block rests, a screw secured to the block and passing through the bottom plate v and a material distance therefrom to form a support, a nut on the screw, a washer of insulating material between the nut and the bottom plate, a block of metal on the insulating block and electrically connected to the screw, a crystal in the block of metal, and a wire having one end in electrical contact with the bottom plate, said wire extending through the block of insulating material and having its end bent over and in contact with the crystal.

2. A crystal detector comprising a block of insulating material, a bottom plate on which the block rests, a screw secured to the block andpassing through the bottom plate and a material distance therefrom to form a support, a nut on the screw, a washer of insulating material between the nut and the bottom plate, a block of metal on the insulating block and electrically connected to the screw, a crystal in the block of metal, a

wire having one end in electrical contact with the bottom plate, said wire extending through the block of insulating material and having its end bent over and in contact with the crystal, and a cover having its bottom portion arranged to frictionally engage the meme? block of insulating .material, the bottom plate having a flange to engage the outer edge of the bottom of the cover.

3. A crystal. detector comprising a block 5 of insulating material, a base plate under the block and flanged at a space from said block, a cover fitting over the block and between the bloek and the flange, a crystal secured to said block, and a Wire secured to the plate and extending through the block and 10 having its end on the crystal.

In testimony that We claim the foregoing, We have hereto set our hands, this 8th day of April, 1922.

GAETANO GRECO. KARL Gr. WOLFF. 

